The objective of the proposed research is to determine whether organic N-acyl compounds other than N-arylacetohydroxamic acids can serve as acyl donors in the metabolic conversion of aromatic hydroxylamines to N-acyloxyarylamines. The objective will be accomplished by synthesizing and evaluating a variety of N-acylated arylamines, arylhydroxylamines and arylalkylhydroxylamines as acyl donors in the metabolic activation of arylhydroxylamines. In vitro hepatic acyltransferase activity will be assayed by the use of N-acetylmethionine to trap activated intermediates formed by acyl transfer from the experimental substrates to arylhydroxylamines. Activity will also be measured by acyl group transfer to p-phenylazoaniline (4-aminoazobenzene). In addition, experiments will be conducted to investigate the reversibility of the deacetylation of arylhydroxyamic acids by hepatic acyltransferase enzymes.